Cortical Bone Trajectory Group Research Articles

A Comparison Between Cortical Bone Trajectory Screws And Traditional Pedicle Screws in Patients With Single-Level Lumbar Degenerative Spondylolisthesis: Five-Year Results.

A retrospective observational study. This study investigated the clinical and radiological results of using cortical bone trajectory (CBT) screws versus traditional pedicle (TP) screws in transforaminal lumbar interbody fusion (TLIF) during a five-year follow-up of patients with single-level lumbar degenerative spondylolisthesis. Few studies have compared five-year follow-up outcomes between CBT screws and TP screws in TLIF. We reviewed outcome data of patients with single-level lumbar degenerative spondylolisthesis who underwent TLIF procedures with CBT screws (131 patients) or TP screws (80 patients) between 2011 and 2015. Patient-reported clinical outcome data included Oswestry disability index scores and visual analog scale (VAS) scores for back and leg pain at baseline, six months, and one year, two years, and five years postoperatively. The radiographic fusion rate and prevalence of secondary surgery for adjacent segment disease were also measured. During the follow-up over five years, the CBT group had significantly lower VAS scores for back pain ( P <0.0001, respectively). At two years after surgery, the CBT group had significantly higher VAS scores for leg pain ( P =0.007). At five years postoperatively, no significant differences existed in the VAS score for leg pain or in the Oswestry disability index score between the two groups. Radiographic fusion rates (CBT vs. TP: 95.5% vs. 95.9%; P =0.881) and adverse events during the five years after surgery were not significantly different. At two years postoperatively, the prevalence of secondary surgery to treat adjacent segment disease was significantly different between the two groups (CBT vs . TP: 13.7% vs. 5.0%; P =0.044). Our results suggest that, during a five-year followup, CBT screws for TLIF were an effective treatment compared to TP screws in the setting of single-level lumbar degenerative spondylolisthesis. However, when using CBT screws for TLIF, surgeons should consider the higher rate of secondary procedures to treat symptomatic adjacent segment disease.

Comparison of Affected-Vertebra Fixation of Cortical Bone Trajectory Screw and Pedicle Screw for Lumbar Tuberculosis: A Minimum 3-Year Follow-Up.

Purpose This study is aimed at comparing the clinical efficacy of cortical bone trajectory (CBT) screw fixation and pedicle screw (PS) fixation of the affected vertebrae in lumbar tuberculosis. Methods We retrospectively analyzed the outcomes in 52 patients (27 cases in the CBT group, 25 cases in the PS group) with lumbar TB who underwent posterior affected-vertebra fixation combined with anterior debridement and bone grafting. The intraoperative blood loss, operative time, visual analog scale (VAS) scores for incision pain and leg pain, Japanese Orthopedic Association (JOA) score, bone grafting fusion, and complications were recorded. Results All patients were followed up for 35-52 months and achieved good clinical outcomes. There were no differences between the two groups in the operative time, intraoperative blood loss, JOA score, bone grafting fusion, and complications. However, there was a significant difference between the two groups in VAS scores for incision pain on the 1st day and 3rd day after surgery. At the last follow-up, JOA scores were significantly improved in both groups compared to the preoperation. Conclusion This retrospective study confirmed that both the affected-vertebra CBT screw fixation and PS fixation for lumbar TB via posterior and anterior approaches could achieve satisfactory outcomes, while the former resulted in better improvement for postoperative VAS scores.

Comparative Outcomes of Cortical Bone Trajectory Screw Fixation and Traditional Pedicle Screws in Lumbar Fusion: A Meta-Analysis

Pedicular screws (PS) often are used in lumbar fusion. Cortical bone trajectory (CBT) is a novel technology in lumbar fusion with less evidence of clinical outcomes. Therefore, we conducted a meta-analysis to compare the efficacy and safety between CBT screw fixation and traditional PS in lumbar fusion surgery. Multiple databases were searched for the articles that compared CBT and traditional PS in lumbar fusion surgeries. Meta-analysis was conducted by RevMan 5.3 software. The following indicators were abstracted: visual analog scale (VAS) scores for back and leg pain, Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) score, surgical duration, complications, and blood loss. The quality of the articles was assessed by the Newcastle-Ottawa Scale or Cochrane Handbook. In total, 25 studies were included, involving a total of 1735 patients. There was no difference in preoperative VAS scores, JOA, ODI, postoperative VAS scores, and fusion rates. In addition, postoperative JOA (mean difference [MD]= 0.78, P= 0.02), ODI (MD= -2.09, P=0.03), surgical duration (MD= -26.90, P= 0.02), complications (MD= 0.70, P= 0.03), and blood loss (MD= -85.27, P= 0.0009) showed greater improvement trends in the CBT group than the PS group, with significant difference. CBT reduced the rate of complications, surgical duration, blood loss, postoperative ODI, and JOA scores. The CBT technique, with better postoperative outcomes, achieved similar fusion rates compared with the PS technique.

Cortical bone trajectory fixation cause low compression force in anterior vertebral column

BackgroundThe cortical bone trajectory (CBT) screws follow a caudocephalad and lateral path from the pedicle to the vertebral body. The bone fusion rate of CBT fixation is equal to or lower than conventional pedicle screw fixation. It remains unclear whether or not CVT screws exert equally compressive forces across the vertebral column. In this study, we intraoperatively examined the insertional torque of CBT screws, and investigated the compression loading and pressure distribution in conventional and CBT fixation using pig bones. MethodsThe insertional torque was measured for a total of 115 CBT screws. Detailed positions of these screws were retrospectively confirmed using CT scans. Screw loosening and interbody fusion were examined 1 year after surgery. In the experiment using pig bones, we inserted screws by conventional trajectory (n = 3) and CBT (n = 4). ResultsMultiple regression analysis showed that the total screw length, the distance from the screw to the medial border of the pedicle and the distance from the superior endplate of the vertebrae were significant independent factors affecting the insertional torque. There was no significant association between the insertional torque and the radiographic bone fusion rate 12 months after surgery. The average pressure and the compression loading in the anterior column were significantly lower in CBT group. ConclusionThese results suggested that the long CBT screws as close to the endplate had high insertional torque, but the anterior column in CBT fixation showed low compression force leading to the insufficient holding intervertebral cage. CBT screws may cause the micromotion of cages, which lowers the bone fusion rate.

Cortical Trajectory Fixation Versus Traditional Pedicle-Screw Fixation in the Treatment of Lumbar Degenerative Patients with Osteoporosis: A Prospective Randomized Controlled Trial.

Study DesignThis was a prospective randomized controlled trial study.ObjectiveTo elucidate clinical and radiographic outcomes and complications of cortical bone trajectory (CBT)-screw fixation in patients with osteoporosis at 24-month follow-up and to compare the results with those after transforaminal lumbar interbody fusion (TLIF) using traditional pedicle screw (PS) fixation.MethodsWe enrolled 124 patients and randomly assigned them to two groups (each group had 62 participants). The primary outcome was fusion rate. Secondary outcomes were VAS, Oswestry Disability Index (ODI), and Japanese Orthopaedic Association (JOA) scores, operation duration, incision length, estimated blood loss, drainage volume, radiological outcomes, and complications.ResultsAt the 6- and 12-month follow-up points, similar fusion rates were observed based on CT scans in both groups (P=0.583 and 0.583). CBT provided significantly better short-term functional status at 3 months postoperation on ODI and JOA scores (P=0.012 and 0) and similar improvements in pain intensity and functional status at other follow-up points. In addition, CBT resulted in significantly better surgical characteristics. Notably, CBT fixation led to lower incidence of screw loosening (P=0.006).ConclusionCBT-screw fixation for single-level lumbar fusion in patients with osteoporosis provided improvement in clinical symptoms comparable to that of TLIF using PS fixation. Significantly better lumbar stability was found in the CBT group. We suggest that CBT-screw fixation is a reasonable and superior alternative to PS in TLIF in osteoporosis.Trial Registration NumberChiCTR1900022658.Date of RegistrationApril 20, 2019.

Comparison of Clinical Outcomes After Transforaminal Interbody Fusion Using Cortical Bone Trajectory versus Percutaneous Pedicle Screw Fixation

The study aim was to compare clinical outcomes between patients undergoing transforaminal lumbar interbody fusion (TLIF) using percutaneous pedicle screw (PPS) and cortical bone trajectory (CBT) by a single surgeon. This was a retrospective matched-cohort study of 77 patients (mean age, 71.7 years; 56% female) who underwent TLIF using CBT or PPS. Thirty-nine consecutive patients in the CBT group and 38 patients in the PPS group were matched for age, sex, and fused levels. All CBT screws were inserted by using a three-dimensional patient-specific guide (MySpine MC, Medacta). Perioperative outcomes of operative time, estimated blood loss, numeric rating scale scores, and serum concentration of creatine kinase were compared between the 2 groups. At 1 year postoperatively, clinical outcomes and radiographic outcomes, including cage subsidence, screw loosening, and fusion rates, were compared between the 2 groups. The numeric rating scale scores on postoperative days 3 and 7 and serum creatine kinase levels on postoperative days 1 and 3 were significantly lower in the CBT group than in the PPS group (all P < 0.005). There were no significant intergroup differences in operation time and estimated blood loss. At postoperative 1 year, there were no significant differences in cage subsidence, screw loosening, and fusion rates between the CBT group and PPS group. Clinical outcomes were equivalent between the 2 groups. The CBT technique using three-dimensional patient-specific guides resulted in lower perioperative pain and quicker recovery after surgery, which suggests that CBT is a less invasive procedure than PPS.

The Rates and Risk Factors of Intra-Pedicular Accuracy and Proximal Facet Joint Violation for Single-Level Degenerative Lumbar Diseases: Cortical Bone Trajectory Versus Traditional Trajectory Pedicle Screw.

A retrospective study. To compare the accuracy of pedicle screw placement and proximal facet joint violation (FJV) in single-level degenerative lumbar diseases using cortical bone trajectory (CBT) and traditional trajectory (TT) techniques, and analyze their possible risk factors. CBT screws have been utilized increasingly to improve cortical bone contact to prevent screw pullout and reduce approach-related morbidity. However, the studies on intra-pedicular accuracy and proximal FJV between the two methods are rare. A total of 40 patients who required single-level instruments were included in the retrospective study treated with the CBT-TLIF and the TT-TLIF at a 1:1 ratio from March 2019 to August 2020. The radiographic outcomes were the intra-pedicular accuracy and proximal FJV. Moreover, the possible risk factors were assessed using bivariate and multivariate analyses. As for the intra-pedicular accuracy, 73 screws (91.3%) were classified as grade A, 7 screws (8.7%) classified as grade B in the CBT group. A total of 71 screws (88.8%) were graded A with remaining 8 screws (10.0%) graded B and 1 screw (1.2%) graded C in the TT group. The proportion of optimal and clinically acceptable screw positions in the two groups were not significantly different (P > 0.05). In addition, the rate of proximal FJV in CBT approach (8.3%) was significantly lower than that in the TT approach (35.0%) (P < 0.001). Multivariate analysis showed the TT insertion approach and facet angle ≥45° were the independent risk factors for proximal FJV, but no factors above affected intra-pedicular accuracy. Compared with the TT approach in TLIF, the CBT approach showed similar intra-pedicular accuracy and remarkable superiority in proximal facet joint protection. Facet angle ≥45° is the independent risk factors for proximal FJV.Level of Evidence: 2.

Effect of posterior lumbar fusion on the degeneration of adjacent segments using cortical bone trajectory screw fixation

Objective: To compare the degenerative changes of adjacent segments after posterior lumbar fusion surgery using cortical bone trajectory (CBT) screws and pedicle screws (PS) in lumbar spinal degenerative disease. Methods: According to certain inclusion and exclusion criteria, prospective non-randomized study on cases of the single-segment lumbar spinal fusion surgery using cortical bone trajectory screws fixation and pedicle screws fixation in Beijing Chao-Yang Hospital from January 2015 to February 2016 was performed. The intervertebral space height (ISH), foramen height (FH), foramen width (FW), cephalad adjacent segment (CAS) and intervertebral disc degeneration grades at MRI scans were measured before surgery and during follow-up. Clinical symptoms were evaluated by Oswestry Dysfunction Index (ODI) score and pain visual analogue scale (VAS) before and during the follow-up. Radiologic adjacent segment degeneration (R-ASD) and symptomatic adjacent segment disease (S-ASD) patients were diagnosed during the follow-up. Paired sample t test was performed when data were compared before surgery and during follow-up. Results: A total of 69 patients were included in the study, 33 in the CBT group (male/female, 15/18), with an average age of (65±11) years, and 36 in the PS group (male/female, 17/19), with an average age of (64±10) years. The follow-up time was no less than 36 months. At the last follow-up, the ISH of the adjacent segments in the CBT group were not statistically different from that before surgery; the ISH of the adjacent segments in the PS group were significantly reduced compared with that before surgery (t=6.78, P<0.05). The loss of ISH, FH, and FW in the adjacent segments in the CBT group were smaller than those in the PS group, and the differences were statistically significant. During follow-up, 4 cases (12.1%) of R-ASD and no S-ASD were found in the CBT group, while 12 cases (33.3%) of R-ASD appeared in the PS group, which was significantly higher than that in the CBT group (χ(2)=4.35, P=0.04). According to MRI, the adjacent discs of PS group had significantly more severe degeneration at the last follow-up than the CBT group (Z=-2.14, P=0.03). Conclusions: Compared with the PS fixation fusion, the CBT screw fixation can effectively reduce the occurrence of adjacent segment degeneration.

Case-control study on cortical bone trajectory screw and pedicle screw internal fixation for the treatment of senile patients with lumbar tuberculosis

To compare clinical effect of cortical bone trajectory (CBT) screw and pedicle screw (PS) internal fixation in treating senile patients with lumbar tuberculosis. From January 2014 to January 2017, 42 senile patients with lumbar tuberculosis were divided into CBT group and PS group, 21 patients in each group. In CBT group, there were 12 males and 9 females, aged from 64 to 81 years old with an average of (72.52±9.25) years old, T value of bone mineral density was (-2.69±0.17) g / cm3, posterior CBT screw internal fixation and anterior debridement, interbody fusion with bone grafting was performed. In PS group, there were 11 males and 10 females, aged from 63 to 85 years old with an average of (71.42±9.81) years old, T value of bone mineral density was (-2.70±0.21) g / cm3, PS internal fixation and anterior debridement, interbody fusion with bone grafting were performed. Length of posterior incision, intraoperative bleeding volume, operation time, time of bone graft fusion and complications between two groups were compared. Level of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), segment kyphotic Cobb angle before and after operation were compared, VAS score was used to evaluate pain releasing, JOA score was applied to evaluate clinical effect. All patients were followed up from 12 to 21 months with an average of (15.00±3.57) months. No reoccurrence of lumbar tuberculosis and screw loosing occurred. There were statistical difference in length of incision, intraoperative bleeding volume, operation time between two groups (P<0.05). Level ofESR and CRP between two groups at 2 weeks, 1 month and 6 months after operation were improved after operation, while there were no differences between two groups (P>0.05). There were no statistical differences in complications, time of bone graft fusion and segment kyphotic Cobb angle at 1 week after operation between two groups (P>0.05). There was difference in Cobb angle at 12 months after operation (P<0.05). For VAS score, there were no difference between two groups before operation and 3 months after operation(P>0.05), but VAS score at 3 months after operation were improved after operation between two groups (P<0.05).For JOA score, there were no difference between two groups before operation, 3 and 12 months after operation, and JOA score at 3 and 12 months after operation were improved than that of before operation between two groups (P<0.05). Both of CBT screw internal fixation and PS screw internal fixation could achieve satisfying results for the treatment of elderly patients with lumbar tuberculosis. PSinternal fixation has a long fixation but great trauma. However, CBT screw internal fixation only needs to fix adjacent segments of the lesion to reduce the fixation range, which has advantages of less trauma and strong screw holding force.

Cortical bone trajectory instrumentation provides favorable perioperative outcomes compared to pedicle screws for single-level lumbar spinal stenosis and degenerative spondylolisthesis

ObjectiveTo compare perioperative outcomes between cortical bone trajectory (CBT) instrumentation with pedicle screws (PS) in patients undergoing laminectomy and posterolateral fusion for single-level lumbar spinal stenosis, and degenerative grade I spondylolisthesis. MethodsA consecutive series of 91 patients from a single institution between January 2017 and July 2019 were retrospectively reviewed. ResultsPatients in CBT group had significantly shorter operative time, lower blood loss and shorter length of stay. ConclusionCBT instrumentation demonstrated favorable perioperative outcomes that may enhance the overall value in patients undergoing laminectomy and posterolateral fusion for single-level lumbar spinal stenosis, and degenerative grade I spondylolisthesis.

Comparison of cortical bone trajectory versus pedicle screw techniques in lumbar fusion surgery: A meta-analysis.

Background:Biomechanical studies have demonstrated that cortical bone trajectory (CBT) screw can provide a 30% increase in uniaxial yield pullout load than pedicle screw (PS). In addition, the insertion torque of CBT screw is 1.71 times higher than that of PS. A meta-analysis was conducted to evaluate clinical results between CBT screw technique and PS technique in lumbar fusion surgery.Methods:An extensive search of literature was performed in PubMed, Embase, the Cochrane library. The following outcomes were extracted: visual analog scale (VAS), Oswestry disabilities index (ODI), Japanese Orthopaedic Association (JOA) score, complications, fusion rates, hospital stay, incision length, blood loss, and operation time. Data analysis was conducted with RevMan 5.3 and STATA 12.0.Results:A total of 12 studies were included in the final analysis. The results indicated that CBT group with less blood loss [P < .01], less hospital stay [P < .01], and less incision length [P < .01] than PS group. There were no significant differences between 2 groups in other clinical parameters and outcomes.Conclusion:CBT technique provided similar clinical outcomes and fusion rates compared to PS technique in lumbar fusion surgery. However, CBT technique provided additional benefits of less blood loss, less hospital stay, and less incision length.

Comparison of Cortical Bone Trajectory Screw Placement Using the Midline Lumbar Fusion Technique to Traditional Pedicle Screws: A Case-Control Study.

Cortical bone trajectory (CBT) screws are an alternative to traditional pedicle screws (PS) for lumbar fixation. The proposed benefits of CBT screws include decreased approach-related morbidity and greater cortical bone contact to prevent screw pullout. Relatively little data is published on this technique. Here, we compare the midline lumbar fusion (MIDLF) approach for CBT screw placement to transforaminal lumbar interbody fusion (TLIF) for traditional PS placement. A prospectively maintained institutional database was retrospectively reviewed for all patients undergoing lumbar spinal fusion using CBT screws over the past 5 years. Controls were identified from the same database as patients undergoing lumbar spinal fusion with traditional PS placement and matched based on age, sex, and number of levels fused. Exclusion criteria included prior lumbar instrumentation. The electronic health record was retrospectively reviewed for demographic, perioperative, and postoperative data. A total of 23 patients who underwent CBT screw placement and 35 controls who received traditional PS were included in the study. The median follow-up time was 52.5 months. The CBT screw group had significantly less mean estimated blood loss than the PS group (186 mL versus 414 mL respectively; P = .008). Both groups experienced significant improvements in preoperative Oswestry Disability Index (ODI) and visual analog scale (VAS) scores for back and leg pain. However, there was no significant difference between the groups in regard to operative time and amount of improvement in VAS pain score or ODI. The CBT group was associated with a significantly shorter mean length of stay (LOS). There were 2 instances of screw pullout in each group. The MIDLF approach with CBT screw placement is associated with less intraoperative blood loss and shorter LOS than traditional PS placement. There is no difference between the 2 techniques in regard to improvement in pain or disability.

Clinical Outcomes After Posterior Lumbar Interbody Fusion: Comparison of Cortical Bone Trajectory and Conventional Pedicle Screw Insertion.

This study is a retrospective cohort study using prospectively collected data. To compare the effectiveness of posterior lumbar interbody fusion (PLIF) using the cortical bone trajectory (CBT) and conventional pedicle screw (PS) techniques. There are few published studies to date comparing PLIF using CBT technique with PLIF using the conventional PS technique. We studied 119 consecutive patients who underwent single-level PLIF between 2010 and 2014 with a minimum 12-month follow-up. Forty-two patients underwent CBT-PLIF (the CBT group) and 77 underwent conventional PS-PLIF (the PS group). Clinical outcomes were assessed by the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and visual analog scale (VAS). To assess perioperative pain, a 6-point Numeric Rating Scale score and the total amount of diclofenac sodium suppositories used were recorded. The operative time and blood loss were recorded. Muscle damage was evaluated by serum creatine kinase concentrations. Fusion status was evaluated using 3-dimensional computed tomography 12 months postoperatively. We used inverse probability of treatment weighting based on the propensity score to reduce confounding factors. There were no significant between-group differences in operative time or fusion rates, whereas the CBT group experienced significantly less blood loss, lower postoperative creatine kinase levels, less diclofenac sodium suppositories, and lower Numeric Rating Scale scores than the PS group did. The change in the JOABPEQ subdomain score for social life function 1 month postoperatively was the only significantly different factor among the JOABPEQ and VAS scores. Both procedures were comparable in terms of clinical outcomes and fusion rates, but CBT-PLIF provided the additional benefits of less blood loss, less intraoperative muscle damage, less perioperative pain, and earlier recovery to normal activities.

Comparison of multifidus muscle atrophy after posterior lumbar interbody fusion with conventional and cortical bone trajectory

ObjectiveTo determine if minimally invasive posterior interbody fusion with cortical bone trajectory (CBT) is associated with reduced paraspinal muscle damage compared to conventional open posterior lumbar interbody fusion (PLIF). MethodsSixteen consecutive patients who underwent CBT were grouped into matched pairs with 16 patients who underwent conventional PLIF between May 2013 and January 2014, in terms of age, sex, body mass index, and spinal levels. Perioperative data and clinical data, including the Japanese Orthopedics Association (JOA) score, visual analogue scale (VAS) score, Oswestry Disability Index (ODI),before and after surgery were evaluated. Magnetic resonance imaging was performed preoperatively and 6 months postoperatively. The fat infiltration ratio was calculated. ResultsThirty-two patients with an 18-month follow-up period were evaluated. Clinical improvement, indicated by the VAS score for back and leg pain, ODI, and JOA score, was significant in both groups. However, there were no significant differences in operative time, blood loss, hospital stay duration, and recovery rate between the groups. The fat infiltration ratio was lower in the CBT group (p<0.05) than in the conventional PLIF group. ConclusionsCBT is comparable with conventional PLIF with respect to short-term clinical outcomes but induced less multifidus muscle damage.